1. Field of the Invention
This invention relates generally to horticultural grafting and is more particularly directed toward a new and improved method and apparatus for making improved graft joints between plant parts, particularly woody plants.
2. Description of the Prior Art
The grafting of a scion upon a rootstock is a common horticultural practice used in the propagation of woody plants. The technique is used widely in the propagation of fruit tree varieties, since bench grafting may be performed during the dormant season of the plant as opposed to field budding during the growing season. Grafting provides the opportunity to build not only the conventional rootstock/scion tree, but also allows for a more complex interstem tree which may have as many as four selected plant materials grafted in series, one upon the other.
In order to graft successfully one plant component to another, it is necessary that the cambium layers of the joined components be in direct contact with one another and that the union be physically strong. The most common technique for grafting woody plant components is by way of a whip graft in which the end of each plant component is cut diagonally at approximately the same angle with a counter-slit made medially and lengthwise through the diagonal cut to form a tongue. The components are then joined so that the tongues are interlocked and the joint is then wrapped by twine or the like. While the whip graft is relatively simple in principle, it requires considerable skill in preparation in order to insure good cambium contact. Further, the strength of the union parallel to the tongue slit is not consistently good and such grafts normally must be tightly wrapped to provide stability.
Accordingly, it is an object of the present invention to provide improvements in grafting techniques. Another object of the invention is to provide a grafting method adapted to produce a structurally strong grafting joint characterized by good cambium contact. A further object of this invention is to provide apparatus to carry out the improved grafting methods on a uniform, highly-repeatable basis.